There are various types of equipment that handle concrete at a job site. Among these are the mixer, typically a hopper with agitator, wherein concrete, grout and/or primers are kept fluid and then pumped or gravity-fed to the point-of-use or to other equipment that will be utilized to feed the concrete to the point-of-use. The hopper/agitator generally includes screws or blades to facilitate such fluidizing. Concrete ready mix trucks are another piece of equipment that handle the mixing and delivery of concrete, wherein the concrete is mixed with water through rotation of a barrel and internal blades or screws.
Once mixed, concrete is generally delivered to the point-of-use. Delivery may be accomplished via the hopper or ready mix trucks as described above, or via the use of a conveyor or hose. Concrete delivered via flexible hoses or metal pipe from a pump located on a trailer or boom pump. Concrete may also be pumped to a deck placer, which has an extension boom and framework that can be transported to support locations within a building undergoing construction, for placement at a specific point on a roof or floor deck.
Most concrete mixing and handling equipment require cleaning for purposes of maintaining useable life of the equipment and for removal of residual set and unset product. Set concrete will interfere with the operation of equipment and the delivery of the concrete product by restricting and impeding movement of the flowable concrete through the equipment. Thus, it is necessary to rinse unset concrete out of the equipment prior to the setting or hardening of the concrete because, once hardened or set, concrete is extremely difficult to remove.
When rinsing the concrete out, an excess amount of water is typically used to carry out the residual concrete and leave the equipment clean. Since concrete mixing and applying equipment is located at a construction site, there is often little or no containment for materials that are discharged either deliberately through cleaning or through spillage. Thus, some means to provide for containment of the concrete and water while being mixed or during cleaning is critical. Once the concrete has been contained in a storage device, it will set and harden. Excess concrete can be reclaimed in this manner for disposal or recycling of its component materials.
Additionally, due to environmental concerns, concrete can no longer be flushed out of ready mix trucks or pumps onto vacant land. The water used for cleaning concrete off tools and equipment may no longer run into storm sewer systems. The responsibility of cleanup and removal of this concrete falls on the ready mix supplier and/or the pump service company.
In addition to cleaning, many concrete delivery methods require the priming of the system. In this operation, the interior walls of the hose or pipe must be coated with a substance that encourages the concrete to flow to the delivery point. A priming agent consists of grout (sand, cement and water), and/or a specialized lubricant. It is usually undesirable for this priming agent to be allowed to enter the concrete pour, as its characteristics differ from the concrete to be applied. This material requires a containment apparatus to collect it, as it comes out of the tip-hose prior to the onset of actual concrete pumping. Currently, this prime is collected in jury-rigged apparatus or forms made by each contractor.
Although various devices and methods for disposal or recycling of residual concrete are known, all are disadvantageous when compared to the present invention.
For instance, U.S. Pat. No. 3,805,535 to Van Weele teaches a method of forming a concrete post in a hole in the ground by placing a bag of water-permeable flexible material designed to block concrete and retain it in the bag. Such a method presents disadvantages, as the concrete remains in the ground and is not recycled.
U.S. Pat. No. 4,016,978 to Danna, Jr. teaches a concrete mixer apparatus for separation and reclamation of gravel, stones, pebbles and the like, from the concrete mixer by suspending the residual concrete in an excess of water with settling of the adjunct materials. However, such a method is disadvantageous, as the aggregates only are reclaimed and the concrete is not, it is water intensive and must be located next to a large batch plant where ready mix trucks return the unused portion of the order.
U.S. Pat. No. 4,154,671 to Borges, U.S. Pat. No. 6,354,439 to Arbore, U.S. Pat. No. 6,155,277 to Barry and U.S. Pat. No. 5,685,978 to Petrick et al. teach the use of screens or strainers to recover cement/concrete and/or aggregates left in concrete mixing and delivery trucks. However, due to the use of such screens to separate the solid materials, these methods are disadvantageous in that they require separate and additional apparatus for transportation of the concrete to be reclaimed or discarded.
U.S. Pat. No. 5,741,065 to Bell et al. and U.S. Pat. No. 6,039,468 to Kowalcyk teach a cleaning system for concrete mixing trucks, wherein the concrete is recycled on-board and, thus, the concrete trucks are highly specialized and disadvantageous in being unable to handle waste from other standard trucks used in the field.
While some or all of the above-referenced patents may well be utilized for reclamation of residual concrete, they do not adequately provide an on-site containment vessel without requiring a large volume for storage of unfilled, heavy and overly complicated rigid vessels. Accordingly, a device and method of containment and reclamation of concrete and related materials is desirable.